Elastomeric tapes are known and used for a variety of purposes. The most common use of elastomeric tapes is as a stretchable backing for a bandage. This is discussed in, e.g., U.S. Pat. No. 3,618,754 (Hoey), which describes a composite structure using a woven layer having elastomeric warp yarns interspersed with flexible warp yarns, the cross or filler yarns are exemplified as cotton. The elastomeric yarns are preferably an elastomeric Spandex.TM. core with a rayon spun outer covering. This tape is complex and difficult to manufacture. Other constructions for bandage tapes are likewise complex with many designed to provide controlled modulus behavior. Namely, a tape is preferred that has only a limited degree of extensibility and then a high modulus value.
Elastomeric tapes have also been proposed for use as electrical insulating tapes based on the electrical properties of rubber as well as their ability to grip a surface, i.e. with their recovery forces when applied under stress. These types of elastic tapes are described, for example, in U.S. Pat. Nos. 3,379,562, 2,559,990 and 3,253,073, which are all described as insulating tapes.
U.S. Pat. No. 2,559,990 describes a basic elastic tape of an elastic film forming polymer with a rubber-resin adhesive coating. The elastomer is described as a plasticized vinyl chloride with a blend of plasticizers in permanent equilibrium with a rubber resin adhesive. When this tape is wound into a roll form a liner is used. This liner must be removed when the tape is used to allow it to adhere to itself.
Elimination of this removable liner is proposed in U.S. Pat. No. 3,379,562, which places a barrier layer on the tape backside which shatters when stretched. This allegedly exposes the rubber and allows tape to adhere to itself when the tape is stretched. However, fragments of the barrier layer can still interfere with adhesion of the tape to itself.
U.S. Pat. No. 3,253,073 describes a tape allegedly designed for high temperature performance. The tape substrate is a laminate of two insulating rubber layers sandwiching a fiber layer. The fibers are brittle and when the tape is stretched sufficiently the fibers break, thereby making the tape elastic in the stretch direction. These fibers are used to improve high temperature performance.
A purely elastomeric tape was also disclosed in U.S. Pat. No. 4,024,312 although no specific uses are proposed. The tape comprises a ABA block copolymer based rubber substrate with a rubber resin adhesive on one side and a release coat on the other. The high extensibility allegedly allows the tape to be easily removed when peeled at substantially 0.degree.. This is stated as a desirable quality for ouchless bandages.
Elastic tapes or tapes with elasticized regions have also been proposed as closures for diapers, and the like, in U.S. Pat. Nos. 4,389,212, 3,800,796, 4,643,729, 4,778,701 and 4,834,820. In U.S. Pat. No. 4,834,820, an elastic tab is provided with either a removable central section or a inelastic cover layer adhered at only the ends of the elastic. When the removable section is removed, the elastic loses its support and is free to stretch. With an unattached central portion of a cover layer, the central portion has a line of weakness which when broken frees the central elastic region. U.S. Pat. No. 4,778,701 also provides an elasticized central region in a composite tape. An elastic strip is adhered to two nonelastomeric anchor strip tapes used to attach either side of the diaper. Complex constructions having features of the above two patents are described in U.S. Pat. Nos. 4,643,729 and 4,389,212. U.S. Pat. No. 3,800,796 describes tapes with elasticized central portions and rigid ends with adhesive layers. All of these tapes are complex multicomponent composites aimed at providing only limited elastic central tape portions.